America’s car insurance price gap: The most expensive and cheapest US cities for car insurance Car insurance costs don’t just depend on your driving record or the car you drive: Your city and ZIP code play an equally important role. Rates can vary by thousands of dollars between towns in the same state, reflecting differences in traffic density, accident frequency, crime rates, weather risks and local insurance laws. CarInsurance.com analyzed these local patterns so drivers can see how their ZIP code or city compares and what factors drive their costs.